1. Clinical Manifestations and Epidemiology
Dengue
Clinical Manifestations and Epidemiology
CENTERS FOR DISEASE CONTROL
AND PREVENTION 1

2. I. Virus, Vector and Transmission2

3. Dengue Virus Causes dengue and dengue hemorrhagic fever
Is an arbovirus
Transmitted by mosquitoes
Composed of single-stranded RNA
Has 4 serotypes (DEN-1, 2, 3, 4) 3

4. Dengue Viruses
Each serotype provides specific lifetime immunity, and short-term cross-immunity
All serotypes can cause severe and fatal disease
Genetic variation within serotypes
Some genetic variants within each serotype appear to be more virulent or have greater epidemic potential 4

5. Transmission of Dengue Virus by Aedes aegypti
Mosquito feeds /
Mosquito refeeds /
acquires virus
transmits virus
Extrinsic
incubation
period
Intrinsic
incubation
period
Viremia
Viremia 5 8 12 16 20 24 28
Illness
Illness
DAYS
Human #1
Human #2 5

6. Replication and Transmission of Dengue Virus (Part 1)
1. Virus transmitted
to human in mosquito
saliva 2
2. Virus replicates
in target organs 4 3
3. Virus infects white
blood cells and
lymphatic tissues
4. Virus released and
circulates in blood 6

7. Replication and Transmission of Dengue Virus (Part 2)6
5. Second mosquito
ingests virus with blood
6. Virus replicates
in mosquito midgut
and other organs,
infects salivary
glands 7 5
7. Virus replicates
in salivary glands 7

8. Aedes aegypti Mosquito8

9. Aedes aegypti Dengue transmitted by infected female mosquito
Primarily a daytime feeder
Lives around human habitation
Lays eggs and produces larvae preferentially in artificial containers 9